Key functions of a legislature include tax reform and foreign policy

Error variance

a. obscures the effects of the variables in which the researcher is primarily interested b. should be maximized c. is always caused by researchers' mistakes d. creates effects that are opposite to those predicted by the researcher e. always leads researchers to draw incorrect conclusions from their data

Credible commitment problems are characterized by a temporal dimension (someone makes a promise today that she does not have an interest in keeping tomorrow) and by the fact that the person making the promise is not the one to benefit from the promise being kept. What are some mechanisms for dealing with credible commitment problems?

A. enforceable contracts B. repeated interactions C. institutions that alter the distribution of power D. all of these